We study the possibility to use line-intensity mapping (LIM) to seek photons from the radiative decay of neutrinos in the cosmic neutrino background. The Standard Model prediction for the rate for these decays is extremely small, but it can be enhanced if new physics increases the neutrino electromagnetic moments. The decay photons will appear as an interloper of astrophysical spectral lines. We propose that the neutrino-decay line can be identified with anisotropies in LIM clustering and also with the voxel intensity distribution. Ongoing and future LIM experiments will have—depending on the neutrino hierarchy, transition, and experiment considered—a sensitivity to an effective electromagnetic transition moment $\sim {10}^{-12}-{10}^{-8}(m_i{c}^2/0.1\mathrm{eV}{)}^{3/2}{\mu }_B$, where $m_i$ is the mass of the decaying neutrino and ${\mu }_B$ is the Bohr magneton. This will be significantly more sensitive than cosmic microwave background spectral distortions, and it will be competitive with stellar cooling studies. As a by-product, we also report an analytic form of the one-point probability distribution function for neutrino-density fluctuations, obtained from the quijote simulations using symbolic regression.

中文翻译：

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用线强映射寻找宇宙中微子背景的辐射衰减

我们研究了使用线强度映射 (LIM) 从宇宙中微子背景中的中微子辐射衰变中寻找光子的可能性。标准模型对这些衰变速率的预测非常小，但如果新物理学增加中微子电磁矩，它可以得到增强。衰变光子将作为天体物理谱线的闯入者出现。我们建议中微子衰变线可以通过 LIM 聚类中的各向异性以及体素强度分布来识别。正在进行和未来的 LIM 实验将具有——取决于中微子等级、跃迁和所考虑的实验——对有效电磁跃迁矩的敏感性$～{10}^{-12}-{10}^{-8}({米}_{\mathrm{一世}}{C}^2/0.1\mathrm{电动汽车}{)}^{3/2}{\mu }_{乙}$， 在哪里 ${米}_{\mathrm{一世}}$ 是衰变中微子的质量和 ${\mu }_{乙}$是玻尔磁子。这将比宇宙微波背景光谱失真更敏感，并且将与恒星冷却研究竞争。作为副产品，我们还报告了中微子密度波动的单点概率分布函数的分析形式，该函数是从使用符号回归的吉诃德模拟中获得的。